Re: [PATCH] userns: Convert xfs to use kuid/kgid where appropriate

Dave Chinner
2013-06-20T00:13:53Z

On Wed, Jun 19, 2013 at 11:09:48AM -0400, Dwight Engen wrote:
> Use uint32 from init_user_ns for xfs internal uid/gid representation in
> acl, xfs_icdinode. Conversion of kuid/gid is done at the vfs boundary,
> other user visible xfs specific interfaces (bulkstat, eofblocks filter)
> expect uint32 init_user_ns uid/gid values.

It's minimal, but I'm not sure it's complete. I'll comment on that
in response to Eric's comments...

> Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
....
> --- a/fs/xfs/xfs_fs.h
> +++ b/fs/xfs/xfs_fs.h
> @@ -347,8 +347,8 @@ typedef struct xfs_error_injection {
> struct xfs_eofblocks {
> __u32 eof_version;
> __u32 eof_flags;
> - uid_t eof_uid;
> - gid_t eof_gid;
> + __u32 eof_uid;
> + __u32 eof_gid;
> prid_t eof_prid;
> __u32 pad32;
> __u64 eof_min_file_size;

The patch doesn't do namespace conversion of these uid/gids, but I'm
not sure it should...

> diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> index 96e344e..70ba410 100644
> --- a/fs/xfs/xfs_icache.c
> +++ b/fs/xfs/xfs_icache.c
> @@ -617,7 +617,7 @@ restart:
>
> /*
> * Background scanning to trim post-EOF preallocated space. This is queued
> - * based on the 'background_prealloc_discard_period' tunable (5m by default).
> + * based on the 'speculative_prealloc_lifetime' tunable (5m by default).
> */
> STATIC void
> xfs_queue_eofblocks(
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 7f7be5f..8049976 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -1268,8 +1268,8 @@ xfs_ialloc(
> ip->i_d.di_onlink = 0;
> ip->i_d.di_nlink = nlink;
> ASSERT(ip->i_d.di_nlink == nlink);
> - ip->i_d.di_uid = current_fsuid();
> - ip->i_d.di_gid = current_fsgid();
> + ip->i_d.di_uid = from_kuid(&init_user_ns, current_fsuid());
> + ip->i_d.di_gid = from_kgid(&init_user_ns, current_fsgid());

Why all new inodes be created in the init_user_ns? Shouldn't this be
current_user_ns()?

Same question throughout - why do you use init_user_ns for all these
UID conversions, when the whole point is to have awareness of
different namespaces?

> xfs_set_projid(ip, prid);
> memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
>
> @@ -1308,7 +1308,7 @@ xfs_ialloc(
> */
> if ((irix_sgid_inherit) &&
> (ip->i_d.di_mode & S_ISGID) &&
> - (!in_group_p((gid_t)ip->i_d.di_gid))) {
> + (!in_group_p(make_kgid(&init_user_ns, ip->i_d.di_gid)))) {
> ip->i_d.di_mode &= ~S_ISGID;
> }
>
> diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
> index 5e99968..daa6127 100644
> --- a/fs/xfs/xfs_ioctl.c
> +++ b/fs/xfs/xfs_ioctl.c
> @@ -981,7 +981,7 @@ xfs_ioctl_setattr(
> * to the file owner ID, except in cases where the
> * CAP_FSETID capability is applicable.
> */
> - if (current_fsuid() != ip->i_d.di_uid && !capable(CAP_FOWNER)) {
> + if (!inode_owner_or_capable(&ip->i_vnode)) {

VFS_I(ip)

> code = XFS_ERROR(EPERM);
> goto error_return;
> }
> diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
> index ca9ecaa..bf96cf8 100644
> --- a/fs/xfs/xfs_iops.c
> +++ b/fs/xfs/xfs_iops.c
> @@ -420,8 +420,8 @@ xfs_vn_getattr(
> stat->dev = inode->i_sb->s_dev;
> stat->mode = ip->i_d.di_mode;
> stat->nlink = ip->i_d.di_nlink;
> - stat->uid = ip->i_d.di_uid;
> - stat->gid = ip->i_d.di_gid;
> + stat->uid = make_kuid(&init_user_ns, ip->i_d.di_uid);
> + stat->gid = make_kgid(&init_user_ns, ip->i_d.di_gid);

Why not:

stat->uid = inode->i_uid;
stat->gid = inode->i_gid;

> stat->ino = ip->i_ino;
> stat->atime = inode->i_atime;
> stat->mtime = inode->i_mtime;
> @@ -488,8 +488,8 @@ xfs_setattr_nonsize(
> int mask = iattr->ia_valid;
> xfs_trans_t *tp;
> int error;
> - uid_t uid = 0, iuid = 0;
> - gid_t gid = 0, igid = 0;
> + kuid_t uid = GLOBAL_ROOT_UID, iuid = GLOBAL_ROOT_UID;
> + kgid_t gid = GLOBAL_ROOT_GID, igid = GLOBAL_ROOT_GID;
> struct xfs_dquot *udqp = NULL, *gdqp = NULL;
> struct xfs_dquot *olddquot1 = NULL, *olddquot2 = NULL;
>
> @@ -522,13 +522,13 @@ xfs_setattr_nonsize(
> uid = iattr->ia_uid;
> qflags |= XFS_QMOPT_UQUOTA;
> } else {
> - uid = ip->i_d.di_uid;
> + uid = make_kuid(&init_user_ns, ip->i_d.di_uid);

uid = VFS_I(ip)->i_uid;
> }
> if ((mask & ATTR_GID) && XFS_IS_GQUOTA_ON(mp)) {
> gid = iattr->ia_gid;
> qflags |= XFS_QMOPT_GQUOTA;
> } else {
> - gid = ip->i_d.di_gid;
> + gid = make_kgid(&init_user_ns, ip->i_d.di_gid);

gid = VFS_I(ip)->i_gid;
> }
.....
> @@ -561,8 +563,8 @@ xfs_setattr_nonsize(
> * while we didn't have the inode locked, inode's dquot(s)
> * would have changed also.
> */
> - iuid = ip->i_d.di_uid;
> - igid = ip->i_d.di_gid;
> + iuid = make_kuid(&init_user_ns, ip->i_d.di_uid);
> + igid = make_kgid(&init_user_ns, ip->i_d.di_gid);
> gid = (mask & ATTR_GID) ? iattr->ia_gid : igid;
> uid = (mask & ATTR_UID) ? iattr->ia_uid : iuid;

Same again - you can just use VFS_I(ip)->i_uid/VFS_I(ip)->i_gid
here.

> @@ -1172,8 +1174,8 @@ xfs_setup_inode(
>
> inode->i_mode = ip->i_d.di_mode;
> set_nlink(inode, ip->i_d.di_nlink);
> - inode->i_uid = ip->i_d.di_uid;
> - inode->i_gid = ip->i_d.di_gid;
> + inode->i_uid = make_kuid(&init_user_ns, ip->i_d.di_uid);
> + inode->i_gid = make_kgid(&init_user_ns, ip->i_d.di_gid);

current name space?

>
> switch (inode->i_mode & S_IFMT) {
> case S_IFBLK:
> diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
> index b75c9bb..94a2a8f 100644
> --- a/fs/xfs/xfs_qm.c
> +++ b/fs/xfs/xfs_qm.c
> @@ -1651,8 +1651,8 @@ xfs_qm_write_sb_changes(
> int
> xfs_qm_vop_dqalloc(
> struct xfs_inode *ip,
> - uid_t uid,
> - gid_t gid,
> + __uint32_t di_uid,
> + __uint32_t di_gid,

xfs_dqid_t

And there's no need to rename the variables - that just causes
unnecessary churn, and the fact it is a dquot ID is documented by
the type.

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com